Patent application title: Direct Current Power Supply

Abstract:

A portable electrochemical power supply for handheld electronic devices,
such as cellular telephones, is disclosed. The power supply includes a
housing with an electrical connector, a circuit board, and a removable
electrochemical cell disposed therein. The circuit board carries power
supply circuitry which receives electrical energy from the
electrochemical cell and provides a power supply output for powering an
external device.

Claims:

1. A power supply, comprising:a housing having an interior surface and an
exterior surface, wherein the housing includes electrical contacts for
receiving power;an electrical connector disposed through said housing,
said connector having a first end accessible from said exterior surface;
anda circuit board disposed within said housing, said circuit board in
electrical connection with the electrical contacts and the connector,
said circuit board receiving an input voltage less than about 1.90V and
providing an output voltage through said connector greater than about
3.00V.

2. The power supply of claim 1, wherein the housing comprises a first
section and a second section, wherein said first section comprises said
connector and defines a first end of said housing, wherein said second
section is tubularly shaped and includes an open end and a closed end,
and wherein said first section is removably joined to the open end of
said second section.

3. The power supply of claim 2 wherein said first section is electrically
nonconductive and said second section is electrically conductive.

4. The power supply of claim 2 wherein said first section is optically
transparent.

5. The power supply of claim 2 wherein said the first end of said
connector is recessed below the first end of said housing.

6. The power supply of claim 1 wherein said housing comprises an opening
therethrough.

7. The power supply of claim 6 wherein said opening allows gas in the
cavity to pass therethrough.

8. A power supply comprising:a housing having an interior surface and an
exterior surface and is cylindrically shaped, wherein the housing
includes a battery cavity, an electrochemical cell and an air gap between
the electrochemical cell and the battery cavity;an electrical connector
disposed through said housing, said connector having a first end
accessible from said exterior surface; anda circuit board disposed within
said housing, said circuit board in electrical connection with the
electrochemical battery and the connector, said circuit board receiving
an input voltage less than about 1.90V and providing an output voltage
through said connector greater than about 3.00V.

9. The power supply of claim 8, wherein the battery cavity has an inside
diameter at least 5% larger than an outer diameter of the electrochemical
cell

10. The power supply of claim 8, further comprising a means for centering
said electrochemical cell within said cavity.

11. A method of assembling a portable battery powered power supply
comprising:(a) placing a circuit board which carries an electrically
conductive member, an electrical connector, a first battery contact, and
electrical circuitry which receives electrical energy from a battery and
generates a power supply output for providing electrical energy to an
external device in a first cover portion so that the electrical connector
aligns with a first opening in the first cover portion;(b) attaching the
first cover portion to a second cover portion having first and second
ends and a battery receiving region disposed therebetween so that the
electrically conductive member makes an electrical contact with the first
end of the first housing;(c) removably attaching a third cover portion
which carries a second battery contact to the second end of the housing.

12. The method of claim 11 wherein the third cover portion is threadedly
attached to the second cover portion.

13. The method of claim 11 wherein the first cover portion is threadedly
attached to the second cover portion;

14. The method of claim 11 including installing, prior to the step of
attaching, an insulating member including a material free region which
aligns with the first battery contact in a recess disposed in the first
end of the second member.

Description:

[0002]This invention generally relates to a portable direct current power
supply for a handheld electronic device. More particularly, this
invention pertains to a direct current power supply for devices such as
cellular phones.

[0003]The proliferation of portable battery powered devices, such as
cellular telephones, has increased dramatically in the last several years
and this trend is expected to continue. The phones typically use a
rechargeable battery that is built into the phone to provide the needed
power. The length of time that the battery powers the phone is dependent
primarily upon the size of the battery and the number of energy consuming
features built into the phone. In response to consumer demand, cell phone
manufacturers incorporate into the phones features such as the ability to
send and receive digital pictures and/or text messages. Unfortunately,
the inclusion of these features usually places additional demands on the
rechargeable batteries that power the cell phones. The net result is that
the cell phones' run times become shorter and shorter due to the
increased power demands. At the same time that the electrical demand
placed on the battery is increasing, the size and weight of cell phones
is decreasing in order to reduce the size of the phones. As the size of
the cell phone is reduced, the size of the battery compartment built into
the cell phone is also reduced. The existence of these two trends (i.e.
increased electrical demand and reduced battery size) has caused many
cell phone users to experience a failed telephone call or data
transmission due to the depletion of their phone's battery at an
inopportune moment. An additional trend that complicates resolving this
problem is that most cell phones require a battery that has specific size
and shape characteristics. In order to encourage consumers to purchase
replacement batteries from the cell phone manufacturer, the cell phones
are made with batteries that have unique shapes, locking mechanisms,
voltage requirements, etc. Furthermore, the recharging port built into
the cell phones limit the type of charger that can be connected to the
cell phone. Collectively, these factors limit the consumer's ability to
rapidly replace the depleted battery with another power supply.

[0004]Numerous attempts have been made to develop a suitable portable
power supply for cellular telephones. For example, U.S. Pat. No.
6,127,801 discloses a power supply that includes a battery pack and a
base unit which has bidirectional circuitry. The battery pack is made to
snap into the base unit which is designed to be clipped onto the cellular
telephone. Unfortunately, the battery pack and base unit tend to increase
the size and weight of the cell phone, which is contrary to the
consumer's desire, while also causing additional proliferation in the
number of components the consumer needs to replace when the phone's
battery is depleted. In another example, U.S. Pat. No. 6,709,784
discloses a unique battery pack that can be plugged into a cellular
phone's contact to recharge the phone's built-in rechargeable battery
and/or directly power the cell phone. This invention bundles the battery
with the plug that allows the battery pack to be connected to the phone.
Consequently, when the battery pack's battery is depleted the entire
battery pack, including the plug, must be discarded which increases the
consumer's cost.

[0005]Therefore, there exists a need for a portable direct current power
supply that uses a commonly available battery that the consumer can
readily insert into and remove from a reusable housing. The power supply
needs to be lightweight, volume efficient and easily adaptable to a wide
array of cell phones that utilize batteries of various shapes and sizes.

BRIEF SUMMARY OF THE INVENTION

[0006]The present invention provides a portable direct current power
supply that can be used to supply an electric current to a handheld
electronic device, such as a cellular telephone, that utilizes a battery
that has a unique size and shape. The present invention is small, light
weight, and inexpensive to operate.

[0007]According to a first aspect of the present invention, a portable
electrochemical power supply includes a housing having an interior
surface and an exterior surface, an electrical connector disposed through
the housing, the connector having a first end accessible from the
exterior surface. The power supply also includes a circuit board disposed
within the housing. The circuit board is in electrical connection with
both the electrochemical cell and the connector, receives an input
voltage from the cell less than 1.90V and provides an output voltage
through the connector greater than 3.00V. The housing includes at least
two sections joined to one another a cavity adapted to removably receive
an electrochemical cell.

[0008]According to another aspect of the invention, a process for
providing an electric current to a battery powered device includes
providing a battery powered device having at least one port physically
and electrically configured to receive an electric current from an
external power supply, selecting an electrochemical cell having a first
terminal, a second terminal and an initial unaltered open circuit voltage
less than 1.90 V, providing a housing for at least one circuit board and
the electrochemical cell, disposing the cell inside the housing, securing
a cover over the open end of the housing, providing an elongated
electrically conductive connector, securing the elongated connector to
the housing and to the device's port thereby establishing an electrical
connection between the housing and the device, and allowing the assembled
housing, elongated connector and device to remain connected while the
circuit board receives an input voltage from the cell and provides an
output voltage to the device. The input voltage is less than 1.90V and
the output voltage is greater than 3.00V. The housing includes an open
end, a sidewall and a closed end. The circuit board is capable of
transforming an electrochemical cell's voltage from a first voltage to a
second higher voltage. The housing also includes an electrically
nonconductive first section defining the closed end of the housing and
through which the electrical connector is disposed and an electrically
conductive second section including the sidewall.

[0009]According to still another aspect, a portable battery powered power
supply includes a first housing portion having a first end which includes
a first opening and a second end, a second housing portion having a third
and fourth ends and a battery receiving region disposed therebetween, a
circuit board, and a power supply circuit carried by the circuit board.
The power supply circuit includes an input which receives electrical
energy from a first battery and an output which provides electrical
energy to a battery powered device. The power supply also includes a
first battery contact carried by the circuit board and which is in
electrical communication with the input of the power supply circuit, an
electrical connector carried by the circuit board and which is in
electrical communication with the power supply output, and a second
battery contact adapted to make electrical contact with a terminal
located at the second end of the battery. The third end faces the first
housing portion, the first battery contact is adapted to make electrical
contact with a terminal located at a first end of a battery received in
the battery receiving region, and the electrical connector is accessible
to an exterior of the power supply through the first opening.

[0010]According to another aspect, a portable battery powered power supply
is adapted to selectively receive first and second generally cylindrical
batteries and supply electrical energy to an external portable battery
powered device through an electrical connector. The power supply consists
essentially of first, second, and third cover portions which lockingly
engage so as to form a unitary assembly having a battery receiving
region, a circuit board, a fourth cover portion, first and second user
operable attachment members carried by the fourth cover portion and which
are adapted to removably attach the fourth cover portion to the unitary
assembly, and a mechanically resilient, electrically conductive member
carried by the fourth cover portion. The circuit board carries power
supply circuitry, the electrical connector, a first battery contact
adapted to make electrical contact with a terminal located on a first end
of the first battery, and a second battery contact adapted to make
electrical contact with a terminal located at a first end of the second
battery. The mechanically resilient, conductive member is adapted to
provide an electrical connection between terminals located at a second
end of the respective first and second batteries. The mechanically
resilient, conductive member is in operative mechanical communication
with the latch members.

[0011]According to still another aspect, a portable battery powered power
supply includes a first polymeric cover portion, a second polymeric cover
portion which lockingly engages the second cover portion so as to form a
unitary assembly which includes a cavity adapted to receive a battery, a
circuit board, and power supply circuitry carried by the circuit board.
The power supply circuit includes an input which receives electrical
energy from a battery and an output for providing electrical energy to an
external device. The power supply also includes a first electrical
connector carried by the circuit board and which is in electrical
communication with the output of the power supply circuitry, a first
battery contact carried by the circuit board and which is in electrical
communication with the input of the power supply circuitry, a third
polymeric cover portion which latchingly engages the unitary assembly so
as to allow a user to selectively access the cavity, and a second battery
contact carried by the third cover portion. The first electrical
connector is adapted to provide a removable electrical connection to a
corresponding external connector, the first battery contact is adapted to
provide an electrical contact with a terminal located at a first end a
battery received in the cavity, and the second battery contact is adapted
to provide an electrical contact with a terminal located at a second end
of the battery.

[0012]According to another aspect of the present invention, a method of
assembling a battery powered power supply includes installing first and
second human operable attaching members and a mechanically resilient,
electrically conductive member in a first cover portion so that the
conductive member urges the attaching members toward an interior surface
of the first cover and provides a first battery contact. The method also
includes snappingly attaching a second cover portion to a third cover
portion to form a housing having first and second ends and a battery
receiving region disposed therebetween, inserting a circuit board which
carries an electrical connector, a second battery contact, and electrical
circuitry which receives electrical energy from a battery and generates a
power supply output for providing electrical energy to an external device
in a fourth cover portion so that the electrical connector aligns with a
first opening in the fourth cover portion. The method further includes
snappingly attaching the fourth cover portion to the first end of the
housing and using the attaching members to removably attach the first
cover portion to the second end of the housing.

[0013]According to another aspect, a method of assembling a portable
battery powered power supply includes placing a circuit board which
carries an electrically conductive member, an electrical connector, a
first battery contact, and electrical circuitry which receives electrical
energy from a battery and generates a power supply output for providing
electrical energy to an external device in a first cover portion so that
the electrical connector aligns with a first opening in the first cover
portion. The method also includes attaching the first cover portion to a
second cover portion having first and second ends and a battery receiving
region disposed therebetween so that the electrically conductive member
makes an electrical contact with the first end of the first housing, and
removably attaching a third cover portion which carries a second battery
contact to the second end of the housing.

[0014]Still other aspects of the present invention will be understood by
those skilled apart upon reading and understanding the appended
description and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0015]FIG. 1 is an exploded cross-sectional view of a portable power
supply;

[0016]FIG. 2 is a cross-sectional view of an assembled portable power
supply;

[0017]FIG. 3 shows a perspective view of a portable power supply, flexible
connector and cellular phone;

[0021]FIG. 7 is a top front perspective view of a portable power supply;

[0022]FIG. 8 is a top front perspective view of a portable power supply
with a cover rendered transparent;

[0023]FIG. 9 is a bottom front perspective view of a portable power supply
with a cover rendered transparent;

[0024]FIG. 10 is a perspective view of a printed circuit board and light
pipe;

[0025]FIG. 11 is a perspective view of the interior of a bottom cover;

[0026]FIG. 12 is a perspective view of the exterior of a top cover;

[0027]FIG. 13 depicts a cross section of a portion of a connector housing;

[0028]FIG. 14 depicts steps in assembling a power supply.

DETAILED DESCRIPTION OF THE INVENTION

[0029]Referring now to the drawings and more particularly to FIG. 1, there
is shown a cross-sectional view of a disassembled portable power supply
20 of this invention. The power supply generally comprises housing 22,
circuit board 24, insulating ring 26, and electrochemical cell 72.
Housing 22 includes an electrically nonconductive first section 28 and an
electrically conductive second section 30 which can be further divided
into first subsection 32 and second subsection 34. First section 28 is
made of an electrically nonconductive and transparent material that will
allow the consumer to view components on the circuit board. Second
section 30 is made of aluminum which is an electrically conductive
material. First section 28 and second section 30 can be secured to one
another. Circuit board 24, commonly known as a printed circuit board
(PCB), generally includes a thin electrically nonconductive disc shaped
base member with a first planar surface 50 and a second planar surface
51. Electronic components, such as resistors, diodes, voltage modifiers,
etc. are printed and/or otherwise attached to either of the base member's
planar surfaces. Secured to the first surface are a tubular metal contact
36 and a light emitting diode 53. Secured to the circuit board's second
surface is an arc shaped electrically conductive contact 99 positioned
adjacent at least a portion of the board's perimeter. The arc shaped
contact 99 on the second surface is in electrical contact with the
electronic circuitry (not shown) secured to either the first planar
surface and/or the second planar surface. A portion of the circuit
board's tubular metal contact 36 extends through opening 38 in interior
wall 40. The diameter of opening 38 is larger than the outside diameter
of the tubular metal contact's distal end 46 but smaller than the
diameter of flange 42 which abuts the inside surface 44 of wall 40
thereby limiting the distance which the tubular contact can extend
through the opening. Wall 40 is sufficiently recessed to prevent the
distal end 46 of tubular contact 36 from extending beyond the plane
defined by the rim 48 of nonconductive first section 28. The insulating
ring, which has an inner diameter that defines the size of opening 27 and
an outer diameter, is made of an electrically nonconductive material.
Ring 26 abuts the bottom 51 of circuit board 24 and ledge 52 in first
subsection 32. The leading edge 54 of first subsection 32 extends past
ring 26 and makes an electrically conductive contact with the arc shaped
electrically conductive contact 99 on the bottom surface of circuit board
24 when the power supply is assembled. First subsection 32 has an outer
diameter 56, an inner diameter 58, a leading end 60 and a trailing end
62. Both the leading and trailing ends are threaded to facilitate
removably securing first subsection 32 to first section 28 and second
subsection 34, respectively. Second subsection 34, also referred to
herein as a cover, is a cup shaped component having a closed end 64 and a
threaded opening 66 opposite the closed end. A coiled electrically
conductive metal spring 68 is secured to the bottom inside surface 70 of
cover 34.

[0030]The assembled power supply disclosed in FIG. 2 may be assembled as
follows. Circuit board 24 is oriented and inserted into the housing's
first section 28 so that the tubular metal contact projects through
opening 38 in the first section's interior wall 40 until the tubular
contact's flange 42 abuts the interior surface 44 of wall 40. Insulating
ring 26 is then inserted into the leading end 60 of the housing's first
subsection 32. The outer diameter of disc 26 is slightly larger than the
first inside diameter 58 of first subsection 32 and slightly smaller than
the inside diameter of ledge 52 thereby insuring that disc 26 rests upon
ledge 52 and does not block the leading edge 54 of first subsection 32.
First section 28 is then secured to first subsection 32 by threading the
first section onto the first subsection thereby trapping disc 26 and
establishing an electrical path between the first subsection's leading
edge 54 and the peripheral contact on the bottom surface 51 of circuit
board 24. To minimize the cost and volume of the power supply, the
housing was designed to eliminate a separate wire or other electrical
conductor that could have been used to complete the electrical circuit
from the cell's second terminal to the circuit board. This was
accomplished by constructing first subsection 32 and second subsection 34
of aluminum which is an electrically conductive material. Other
electrochemically conductive materials, such as nickel plated steel,
copper or brass could be used instead of aluminum. If desired, the
housing could be made of an electrically nonconductive material, such as
plastic, provided an electrically conductive path is provided between the
cell's second terminal and the circuit board. The electrically conductive
path could be a thin, elongated strip of brass secured to the interior
surface of the nonconductive housing and which wraps around or otherwise
terminates at the leading edge 54 of the housing so as to make electrical
contact with the arc shaped contact 99 of the PCB. Electrochemical cell
72 is then inserted into cavity 74 so that the cell's first terminal 76
extends through opening 27 in insulating disc 26 and contacts a centrally
located electrical contact on the bottom surface of circuit board 24. The
disc prevents electrical contact between the first terminal and other
electronic components that may be located on the bottom of the circuit
board. Second subsection 34, also referred to herein as a cover, is then
secured to the trailing end 62 of first subsection 32 by manually
rotating the cover around the periphery of the first subsection's outer
wall so that the threaded ridges 80 on the outer surface of the first
subsection engage the grooves 82 in the inner surface of the cover.
Spring 68 forces the cell toward the circuit board thereby insuring the
establishment and maintenance of good physical contact between the cell
and the circuit board while also providing an electrically conductive
path between the cell's second terminal and the cover.

[0031]Secured to the circuit board are the components of an electronic
circuit 300. The components may be secured to the circuit board's first
side 50, which is the side of the circuit board furthest away from the
electrochemical cell, or to the circuit board's second side 51, which is
located closest to the cell.

[0032]A first portion of the circuit functions as a sensing circuit and a
second portion of the circuit functions as a boost circuit. The basic
function of the sensing circuit is to detect the presence of a battery
powered device to which the power supply is connected and then determine
whether or not the electrochemical cell secured within the power supply's
housing will be able to provide a current with sufficient amperage and
voltage to operate the device and/or recharge a rechargeable battery that
forms a part of the device. If one or more of the device's electrical
characteristics that the sensing device can detect, such as electrical
resistance, is not acceptable to the sensing circuit, the sensing circuit
will not allow the boost circuit to supply power to the device.
Similarly, if the sensing circuit determines that the cell's
electrochemical capacity has been sufficiently depleted to prevent the
cell from providing an adequate current to the boost circuit, then the
sensing circuit will not allow the boost circuit to operate. In one
embodiment, the sensing circuit can be made to attempt to detect the
presence of a suitable device and electrochemical cell approximately two
times per second. From the consumer's point of view, the power supply is
always "on". However, since the drain on the cell that powers the sensing
circuit is very small the cell can power the sensing circuit for long
periods of time before the cell must be replaced.

[0033]The function of the boost circuit is to transform the cell's
voltage, which is also referred to herein as the boost circuit's input
voltage, from a first voltage to a second higher voltage. Preferably, the
boost circuit's input voltage, which is defined as the cell's closed
circuit voltage prior to discharging the cell in any circuit that
depletes more than one percent of the cell's theoretical electrochemical
capacity, is below 1.90V. The boost circuit receives the cell's energy,
which has a voltage below 1.90V, and transforms it to produce an output
voltage greater than 3.00V which is the minimum voltage needed to power
many commercially available cellular telephones. If desired, the boost
circuit could be configured to transform the output voltage to a
different voltage such as 3.60V. The boost circuit is not activated until
the sensing circuit determines that the cell's output voltage and the
device's electrical characteristics meet predefined criteria such as a
minimum closed circuit voltage for the cell and a maximum electrical
resistance for the device.

[0034]With reference to the functional block diagram of FIG. 5, the
electronic circuit 300 is in operation operatively connected between the
electrochemical cell 72 and a battery 310 which powers an electrical
device 88 such as a cellular telephone.

[0035]The electronic circuit 300 is powered by the electrochemical cell
72. The electronic circuit 300 converts the energy provided by the
electrochemical cell 72 to a voltage and current level suitable for
providing power to the electrical device 88.

[0036]In one embodiment, the electronic circuit 300 receives input power
from an alkaline AA cell having a nominal voltage of 1.5 volts direct
current (VDC) and produces an output voltage greater than about 3.0 volts
direct current (VDC). More particularly, the circuit 300 provides charge
current to a lithium ion battery 310 having a nominal voltage of 3.6
volts direct current (VDC). The electronic circuit 300 includes a
controller 306 operatively connected to charging/boost circuitry 307
which in turn provides electrical energy to the lithium ion battery 310.
Input sense circuitry 302 is operatively connected to the electrochemical
cell 72 and provides the controller 306 with an indication of the voltage
supplied by the cell 72. Load sense circuitry 304 is operatively
connected to the load 310 and provides the controller 306 with a signal
indicative of the current drawn by the load 310. A human readable
indicator 308 such as one or more light emitting diodes (LEDs) indicates
the status of the power supply.

[0037]An exemplary graph showing the relationship between the output
current and voltage supplied to the lithium ion battery 310 and the input
voltage supplied by the electrochemical cell 72 is shown in FIG. 6. Over
a first range of voltages near the nominal 3.6 volt direct current (VDC)
voltage of the lithium ion battery 310, the circuit 300 functions as a
current source to provide a substantially constant charging current to
the battery 310. As the battery 310 voltage increases with increasing
battery charge, the current supplied to the battery 310 is reduced until
the battery 310 is substantially charged.

[0038]With continuing reference to FIG. 5, the electronic circuit 300 also
includes input sense circuitry 302 which senses the input voltage
provided by the electrochemical cell 72. Above a first threshold voltage,
for example approximately 1.1 volts direct current (VDC), the current
supplied by the charging circuitry 307 remains substantially constant as
a function of input voltage. As the cell 72 voltage decreases, the
current supplied by the charging circuitry 307 likewise decreases. As the
cell 72 voltage decreases below a second threshold, for example
approximately 0.6 volts direct current (VDC), the controller 306 enters
an idle mode or low power mode in which the boost circuit 307 is disabled
and the charging circuitry 307 no longer supplies power to the lithium
ion battery 310.

[0039]The load sensing circuitry 304 senses the presence of a load at the
circuit's output. If no load is detected, the controller 306 enters an
idle or low power mode in which the boost circuitry 307 is disabled so as
to conserve energy in the cell 72. If, on the other hand, the load
sensing circuit 304 indicates the presence of a suitable load, the boost
circuit is enabled, and the electronic circuitry 300 provides a
recharging current to the battery 310. The controller 306 causes the
indicators 308 to flash to indicate that the device is providing power to
the load.

[0040]In one embodiment, the electronic circuit 300 is implemented using
the TEC103 integrated circuit available from Techtium Ltd. of Tel Aviv,
Israel. Of course, other embodiments of the circuit can also be
implemented.

[0041]While the above description has focused on recharging the lithium
ion battery 310, the electronic circuit 300 may also provide an
additional or auxiliary power source while the electrical device 88 is
operational, or may be used to power the device directly.

[0042]Other embodiments of the electronic circuit 300 may also be
implemented. Thus, for example, the circuit may be configured to provide
voltage and/or current levels suitable for charging battery technologies
other than lithium ion. The circuit may be configured to provide a
suitable voltage and/or current to directly power a load in the absence
of a battery 310. Moreover, one or both of the input and load sense
functions may be omitted.

[0043]Shown in FIG. 3 is an exploded view of the following three articles:
a portable power supply 20 of this invention; an elongated, flexible,
electrically conductive connector 86; and a cellular telephone 88. Power
supply 20 includes a transparent first section 28 through which can be
seen two light emitting diodes 53; tubular metal contact 36 and circuit
board 24. Located between one end of tubular contact 36 and printed
circuit board 24 is spring contact 92 which is electrically isolated from
tubular contact 36. Spring contact 92 is electrically connected to one of
the electrochemical cell's terminals and tubular contact 36 is
electrically connected with the cell's other terminal. Flexible connector
86 includes first connecting means 94 on one end thereof and second
connecting means 96 on the opposite end thereof. The connecting means are
electrical plugs that can be used to establish electrical connection
between a power supply and a device. The two plugs are electrically
connected and physically secured to one another by a flexible wire that
includes a metal conductor coated by an electrically nonconductive
material. First connecting means 94 includes an outer insulated portion
102, a first conducting portion 104, a second conducting portion 106 and
an insulating sleeve 108. First conducting portion 104 is a tubular metal
contact that is designed to form an interference fit with the inside
diameter of tubular contact 36. Insulating sleeve 108 lines the inside
surface of first portion 104 and extends slightly beyond the distal end
of first portion 104 thereby forming an electrically insulated path
through which second conducting portion 106 extends. When the consumer
grasps outer insulated portion 102 and inserts first connecting means 94
into the power supply's tubular metal contact 36, first conducting
portion 104 establishes electrical contact with tubular contact 36 and
second conducting portion 106 establishes electrical contact with spring
92. Second conducting means 96 is sized to fit in the cavity defined by
port 110 in cellular telephone 88. Because manufacturers of cellular
phones may use one of several different ports, and each port is uniquely
sized relative to the other ports, the consumer needs to select a
flexible electrically conductive connector that has a second connecting
means that is properly configured to match the port in their phone. If a
consumer needs to sequentially power two different cellular telephones
with different size ports, such as could occur when the consumer
exchanges their old cell phone for a new cell phone, the power supply is
still usable provided a flexible connector that will fit the new phone is
selected. When the flexible connector's first connecting means is plugged
into the power supply's tubular contact and the second connecting means
is plugged into the device's port, the power supply's sensing circuit
detects the cellular phone and allows the power supply to send a current
to the phone provided one or more predefined characteristics are detected
by the sensing circuit.

[0044]As shown in FIG. 4, a process of this invention includes the
following steps. In step 200, providing a battery powered device. The
device includes a port to which an electrically conductive connecting
means can be secured. In step 202, assembling a portable power supply.
The power supply includes a housing having a removable electrochemical
cell disposed therein. In step 204, an elongated electrically conductive
connector is provided. The connector has a first connecting means secured
to one end and a second connecting means secured to the other end of the
connector. Step 206 represents securing the first connecting means to the
power supply and the second connecting means to the device's port. In
step 208, the device, elongated connector and power supply are allowed to
remain connected while the printed circuit board receives an input
voltage from the cell and provides an output voltage to the device
wherein the input voltage is less than 1.90V and the output voltage is
greater than 3.00V.

[0045]A preferred battery for use in a portable direct current power
supply of this invention is a single primary cylindrical battery that
incorporates a single anode that includes lithium, a single cathode that
includes iron disulfide and a nonaqueous electrolyte. The preferred
battery has a jellyroll construction wherein strips of the anode
(lithium), cathode (iron disulfide) and separator are rolled to form a
coil which is then inserted into the container that forms the body of the
cell. Jellyroll cells are known to have high anode-to-cathode interfacial
surface area which facilitates high rate discharge. In a preferred
embodiment, at least 20 percent of the cell's theoretical electrochemical
capacity is discharged at 1.40V or higher and the cell has an initial
unaltered open circuit voltage between 1.50V and 1.90V. Other suitable
cell chemistries include: (1) a primary cylindrical cell that
incorporates zinc, an alkaline electrolyte and one or more
electrochemically active materials selected from the group consisting of
manganese dioxide, nickel oxyhydroxide and silver oxide; (2) a metal/air
cell that incorporates zinc, an alkaline electrolyte and has air access
port(s) and/or an air manager; (3) rechargeable cells that utilize an
alkaline electrolyte and electrodes that include nickel and cadmium or
nickel and a metal hydride; and (4) cells that utilize a zinc anode,
manganese dioxide in the cathode and an acidic electrolyte. To
accommodate commercially available cell sizes, the power supply's housing
is made to define a cylindrical cavity that will accept a single
electrochemical cell, also referred to herein as a battery, such as an R6
(AA), R03 (AAA), R14 (C) or R 20 (D) size battery. Because the power
supply utilizes commonly available batteries, there is no need to
purchase several uniquely shaped batteries to power several different
devices owned by a consumer. The power supply of this invention allows
the consumer to use a single power supply to sequentially power many
different devices.

[0046]One of the issues that may need to be considered in the design of a
power supply that includes an electrochemical cell is the management of
heat that is generated when the cell is discharged. For example, when an
R6 size battery that includes zinc, manganese dioxide and an alkaline
electrolyte is continuously discharged at a one amp constant current
drain rate, the exterior surface of the cell can heat up to 45° C.
If the peripheral surface of the cell contacts the interior surface of
the power supply's housing, heat will be conductively conveyed to and
through the cell's housing. If the power supply is then picked up by an
unsuspecting consumer, such as a child, the elevated temperature of the
power supply's housing could cause the consumer to suddenly drop the
power supply resulting in harm to the consumer and/or damage to the power
supply and/or device. One way to safely manage the heat generated by the
battery is to minimize the contact between the recently discharged cell
and the interior surface of the housing, particularly the amount of
contact between the interior surface of the housing's sidewall and the
battery's circumferential surface. Preferably, contact between the cell's
circumferential surface area and the sidewall of the housing is limited
to less than 5% of the cell's circumferential surface area which would
insure that at least 95% of the cell's circumferential surface area does
not contact the interior surface of the housing. This can be accomplished
by incorporating into the housing a mechanism that centers the cell in
the cavity upon insertion of the cell and then keeps the cell centered in
the cavity regardless of how the power supply is oriented by the
consumer. For example, insulating disc 26 (see FIG. 1) could be made of a
sufficiently thick material to allow for the formation of ridges and/or
grooves in the bottom surface 51 thereof that would limit side-to-side
movement of the cell's first terminal 76 thereby restricting lateral
movement of the cell. Similarly, the interior bottom surface 70 of cover
34 could be contoured to engage ridges and/or recesses on the cell's
second terminal 78 and thereby prevent lateral movement of the cell in
the cavity. Another way to manage the transfer of heat from the cell to
the power supply's housing is to insert a tubularly shaped thermal
insulator between the cell and the interior surface of the housing's
sidewall. The diameter of the tubularly shaped insulator would need to be
greater than the diameter of the cell and less than the inside diameter
of the housing. Alternatively, a thermally insulating material could be
applied to the housing's exterior surface. Yet another way to manage heat
transfer is to insure that the inside diameter of the housing is at least
5% larger than the outside diameter of the cell thereby insuring the
existence of an air gap between the housing and the cell's
circumferential surface area.

[0047]The housing of the power supply shown in FIG. 1 could be made with
one or more openings through the housing to facilitate the movement of
gases, such as oxygen and/or hydrogen, into or out of the housing.
Certain batteries, such as cylindrical batteries that include powered
zinc, manganese dioxide and an alkaline electrolyte, are known to produce
hydrogen gas during discharge. The gas slowly escapes through the
battery's housing by permeating through the cell's seal assembly.
Openings through the power supply's housing will allow the gas to escape
thereby avoiding a dangerous buildup of hydrogen gas in the power
supply's housing. Another reason to incorporate openings through the
housing is to allow oxygen in the air to access the electrochemical cell
if the cell is an air cell which uses the oxygen as one of the cell's
reactants. The oxygen would flow through openings in the power supply's
housing and then through the openings in the electrochemical cell's
housing where the oxygen could react with the cell's other
electrochemically active material to produce an electric current. The
openings could also be used to dissipate the heat generated by the cell
as it is discharged.

[0048]Because the power supply of the present invention is intended for
use by consumers in their day-to-day activities when the device and power
supply may be temporarily stored in a purse, briefcase or coat pocket,
the total volume occupied by the power supply needs to be minimized. Thus
the volume occupied by the housing should be minimized relative to the
volume occupied by the electrochemical cell. Preferably, the volume of
the electrochemical cell should be at least 85% of the total volume
occupied by the power supply. More preferably, the volume of the
electrochemical cell should be at least 90% of the total volume occupied
by the power supply. To accomplish this objective, a power supply of this
invention is preferably designed to include an electrochemical cell
having an outer diameter that is no less than 95% of the inside diameter
of the cavity into which the cell is inserted.

[0049]The operation of a preferred power supply of this invention will now
be described. A primary (nonrechargeable) battery having a first terminal
electrically connected to a single anode, a second terminal electrically
connected to a single cathode, and an unaltered open circuit voltage
below 1.90V, is inserted through an opening into a partially enclosed
housing that includes a printed circuit board and an electrical connector
disposed through the housing. A cover is secured over the opening thereby
providing an electrically conductive path between the cell's second
terminal and an electrically conductive portion of the housing that
establishes an electrical connection with the printed circuit board. The
printed circuit board includes a sensing circuit that detects the
presence of a properly inserted cell having a minimum voltage. The
printed circuit board further includes a light emitting diode that is
illuminated for a brief period of time to signal the consumer that the
power supply is operational. The consumer then secures one end of an
elongated electrically conductive connector to the power supply's
electrical connector that extends through the housing and the second end
of the elongated connector is secured to a cellular telephone's charging
port. The power supply's sensing circuit detects the presence of a cell
phone that can be recharged by the power supply and then activates the
printed circuit board's boost circuit which increases the cell's voltage
from less than 1.90V to 3.00V or higher. The power supplied by the power
supply is used to recharge the cell phone's rechargeable battery and/or
to directly power the cell phone. The sensing circuit monitors the cell's
voltage and reduces or stops the power supply's output if the cell's
voltage falls below a predetermined minimum voltage. For example, if the
cell's voltage drops below a first threshold voltage, such as 1.10V, then
the power supply's output is reduced. When the cell's voltage drops below
a second threshold voltage, such as 0.60V, then the power supply's output
is reduced to 0.0V.

[0050]Turning now to FIG. 7, a portable power supply 700 has top 702,
bottom 704, front 706, rear 708, and first 710 and second sides 712. As
the power supply 700 is readily portable, the foregoing descriptions are
intended to provide a consistent frame of reference with which to
describe the power supply itself 700 and do not necessarily correspond to
the reference frame of a user or otherwise to the external environment.
As illustrated in FIG. 7, the power supply 700 is adapted to receive two
(2) AA size cells. Also as illustrated, the power supply 700 has exterior
dimensions of 83.4 millimeters length×41 millimeters
wide×22.8 millimeters deep and takes the shape of an ovoid having
generally flattened front 706 and rear 708 surfaces.

[0051]The power supply 700 includes a front cover 714, rear cover 716, a
top cover 718, and a bottom cover 720 which may advantageously be molded
or otherwise formed using a polymer such as acrylonitrile butadiene
styrene (ABS). Accessible through an opening which is generally centered
in the top surface of the top cover 718 is an electrical connector 722
such as a female jack. A first human readable status indicator 724a is
visible on the first side 710 of the top cover 718. A corresponding
second human readable status indicator 724b (see FIG. 9) is likewise
visible on the second side 712. A first latch 726a is located at the
front 706 of the bottom cover 720. A corresponding second latch 726b
(again not visible in the perspective view of FIG. 7) is likewise located
at the rear 708 of the bottom cover 720.

[0053]Protrusions 808 and recesses 810 disposed at the periphery of the
rear cover 716 snappingly engage corresponding recesses and protrusions
disposed at the periphery of the front cover 714. More particularly, the
clips and recesses are configured to facilitate assembly of the cover
portions 714, 718 into a unitary assembly but to resist ready disassembly
by a user.

[0054]With additional reference to FIG. 11, the bottom cover 720 is
removably attached to the power supply 700 so as allow a user to insert
and remove the batteries. The bottom cover 720 carries the latches 726a,
726b, which are preferably identical, and the contact member 820.

[0055]The latches 726a, 726b include user operable actuating portions
812a, 812b which are accessible through respective material free regions
in the bottom cover 720. As illustrated, the actuating portions 812a,
812b are substantially flush with the outer surface of the cover 720. The
latches 726a, 726b also include shoulder portions 1102a, 1102b having a
dimension greater than that of the material free regions and which aid in
retaining the latches 726a, 726b in position inside the cover bottom
cover 720.

[0056]The latches 726a, 726b also include cover engaging portions 814a,
814b which extend upwardly from the bottom cover 720. The cover engaging
portions 814a, 814b include recesses 816a, 816b, material free regions,
catches, or the like which engage corresponding protrusions disposed in
the inner surface of the front 714 and rear 716 covers. The respective
protrusions have generally curved or wedge shaped profiles so that the
height of the protrusions is relatively lower near the bottom of the
respective covers and relatively higher near the top. As will be
appreciated, such an arrangement facilitates the assembly of the bottom
cover 720 to the front 714 and rear 716 covers but prevents ready
disassembly unless the actuating portions 812a, 812b are depressed. The
cover engaging portion 814a, 814b may also be configured to provide a
protrusion which engages a corresponding recess or latch portions on the
covers 714, 716.

[0057]The contact member 820 is fabricated from an electrically
conductive, resilient material such as AISI 302 chromium nickel stainless
steel. The contact member 820 is supported by a boss 822 which extends
generally inwardly from the bottom inner surface of the bottom cover. A
post 824 extends through a corresponding aperture in the contact member
820 so as to aid in positioning the contact member 820. The post 824 may
be heat staked or otherwise deformed so as to hold the contact member 820
in place. Other fastening techniques, such as a split post which
snappingly engages the aperture, mechanical fasteners such as screws,
adhesives, and/or interference fits are also contemplated.

[0058]The contact member 820 includes tabs 826a, 826b which engage
corresponding slots or recesses in the inner portion of the latches 726a,
726b. The resilient nature of the contact member 820 tends to urge the
latches 726a, 726b outwardly toward the bottom cover 720 until their
respective shoulders 1102a, 1102b contact the inner surface thereof. The
contact member 820 also includes first 828a and second 828b battery
contacts which provide electrical connections to the terminals of
batteries inserted in the battery receiving region 802. The resilient
nature of the contact member aids in providing a reliable electrical
connection with batteries installed in the battery receiving region 802.

[0059]As illustrated, the bottom cover 720 and associated components have
rotational symmetry so that the contact member 820 may be installed in
the bottom cover in either of two (2) 180° rotationally opposed
positions; the cover latches 726a, 726b are interchangeable. Moreover,
the bottom cover 720 may be likewise installed on the power supply in
either of two (2) 180° rotationally opposed positions. A
particular advantage of such a configuration is that assembly of and
installation of the bottom cover 720 on the power supply 700 is
simplified.

[0060]Returning now to FIGS. 8 and 9 and with additional reference to FIG.
10, the top cover 718 includes first 902a and second 902b attaching
members which snappingly engage the rear 716 and front 714 covers,
respectively. The attaching members 902a, 902b are preferably keyed so
that the top cover 718 cannot be installed in the incorrect orientation.
More particularly, the first attaching member 902a includes a generally
square aperture which is adapted to engage a correspondingly shaped
protrusion 904a on the inner surface of the rear cover 712. The second
attaching member 902b likewise includes a generally circular aperture
which is adapted to engage a correspondingly shaped protrusion on the
inner surface of the front cover 714. The respective protrusions 904 have
generally wedge shaped profiles so that the height of the protrusions is
relatively lower near the top of the respective covers and relatively
higher near the bottom. As will be appreciated, such an arrangement
facilitates the assembly of the top cover 718 to the front 714 and rear
716 covers but prevents ready disassembly by the user or otherwise.

[0061]A PCB 908 is carried by the top cover 718. Disposed on a first side
912 of the PCB 908 are first and second battery contacts 906a, 906b which
are adapted to make electrical contact with the respective terminals of
batteries inserted in the battery receiving region 802. Battery polarity
members 910, which extend from the inner surfaces of the front 714 and
rear 716 covers, prevent the battery located nearer the first side 710
from being inserted with the improper polarity. More particularly
polarity members 910 associated with each of the front and rear covers
cooperate to form an aperture 998 of a size which allows the positive
terminal of a desired size battery (AA in the illustrated embodiment) to
protrude through the aperture 998 so as to contact the first battery
terminal 906a. The aperture 998 has a dimension smaller than the outer
diameter of the desired size battery so that the negative terminal cannot
make such a contact.

[0062]The PCB 908 also carries power supply circuitry which converts the
energy supplied by the batteries to the desired voltage and/or current
levels at the power supply output. In one implementation, the power
supply circuitry may function substantially as described above in
connection with the circuit board 24 and the circuitry 300. As
illustrated in connection with FIGS. 7-11, however, the batteries are
connected electrically in series. Consequently, the power supply circuit
input voltage is ordinarily twice that provided to the circuitry of
circuit board 24 such that the operation of the circuitry 300 would be
adjusted accordingly. One consequence of such an arrangement is that the
power supply 700 may advantageously be used to supply GSM mobile phones
and other electrical appliances having relatively higher power
requirements than can be effectively supplied by only a single battery.

[0063]FIG. 10 depicts the second side 914 of the PCB 908, the connector
722, light sources 1001a, 1001b such as light emitting diodes (LEDs), and
a light pipe 1002. The connector 722, which is electrically connected to
the output of the power supply circuit, is carried on the second side 914
of the PCB 908. The connector 722 is positioned to align with a
corresponding opening in the top cover 724 when the PCB 908 is installed
in the power supply 700 so that the connector is accessible from the
exterior thereof. Keys 1008a, 1008b, which engage corresponding slots in
the inner surface of the top cover 718, prevent the PCB 908 from being
installed in the incorrect orientation.

[0064]As illustrated, the connector 722 also includes a generally tubular
or cylindrical portion 1098 which passes though a material free region of
the light pipe 1002. The exterior of the light pipe 1002, which is
fabricated from polycarbonate or other suitable material, has generally
bow or arcuate shape which generally conforms to the shape of the top
cover 718 so that the light pipe may be inserted therein. The exterior
surface of the light pipe 1002 includes grooves or slots 1004 which
engage corresponding bosses which protrude inwardly from the inner
surface of the top cover 718 so as to aid in properly positioning the
light pipe 1002.

[0065]The light sources 1001a, 1001b, which are electrically connected to
the power supply circuit so as to provide an indication of the circuit
status, are positioned so that, when the PCB 908 and the light pipe 1002
are installed in power supply, the light sources 1001a, 1001b are in
optical communication with corresponding light receiving portions 1006a,
1006b of the light pipe 1002. The light pipe 1002 further aligns with a
light transmissive or material free region of the top cover 718 so as to
provide the status indicators 724a, 724b which are visible therethrough.
Additionally, some or all of the annular portion 1096 of the light pipe
1002 may be disposed so as to be visible between the cylindrical portion
1098 of the connector 722 and the corresponding material free region of
the top cover 718. Such an arrangement can be used to provide an
additional human readable indication at the top of the power supply 700.
As illustrated, the top cover 718 and light pipe 1002 have rotational
symmetry so that the light pipe 1002 may be installed in the bottom cover
in either of two (2) 180° rotationally opposed positions

[0066]An alternative implementation of the top cover 718 which facilitates
the use of a rotationally locking external connector is illustrated in
FIG. 12. A described above, the top cover 718 includes an aperture 1202
which aligns with and provides access to the connector. As shown in FIG.
12, however, the cover includes 180° opposed shelf or lip portions
104a, 1204b located at or near the top surface of the top cover 718 at
which the aperture 1202 has a relatively smaller diameter. Stated another
way, the cover also includes 180° opposed material free regions
1206a, 1206b located at or near the top surface of the top cover 718 at
which the aperture has a relatively larger diameter. Additional lips or
shelves 1208a, 1208b which restrict the aperture to a smaller diameter
are disposed below the material free regions 1206a, 1206b.

[0067]A portion of the housing of a corresponding external connector has
the cross section shown in FIG. 13. The housing includes lips or shelves
1302a, 1302b which are sized to fit through the material free regions
1206a, 1206b. The location and depth of lips 1302a, 1302b are selected so
that the connector may be inserted in the aperture 102 and rotated so as
to prevent the external connector from being removed from the power
supply 700. Though illustrated to provide a 90° rotationally
locking connector, the aperture and external connector may readily
configured to provide 180° or other desired locking actions. Such
an arrangement may likewise be implemented in connection with cover 28.

[0068]In one embodiment, the front 714 and rear 716 covers and the latches
726 are provided in first color, while the top 718 and bottom covers 720
are provided in a second color. Logos, instructions, additional
decorative features or other similar items may also be provided on the
outer surface of the housings, for example through additional molded
plastic pieces suitably fastened thereto. The top cover 718 especially
may also be rendered translucent or transparent.

[0069]Still other variations are possible. For example, the power supply
700 may be configured to receive AAA, C, D, or other sized batteries. The
power supply may also be configured to accept four (4) or more batteries,
or also only a single battery, provided that an electrically conductive
path is provided between the cell's second terminal and the PCB 908.

[0070]Assembly of the power supply will now be described in relation to
FIG. 14. At 1402, the front 714 and rear covers 716 are attached to form
a housing body. In the illustrated embodiment, the covers are snapped
together such that the protrusions 808 and recesses 810 engage.

[0071]At 1404, the light pipe 1002 and PCB 908 are inserted in the top
cover 718. Stated another way, the top cover is placed over the light
pipe 1002 and PCB 908. Note that the light pipe may be installed in
either of two 180° opposed positions. The PCB, however, is keyed
and may be inserted in only a single rotational position.

[0072]At 1408, the top cover 718 is attached to the housing body. In the
illustrated embodiment, the pieces are snapped together such that the
attaching members 902 engage their corresponding protrusions 904. Note
that the top cover 718 and the housing body can be attached in only a
single rotational position.

[0073]At 1406, the latches 726a, 726b and the contact member 820 are
installed in the bottom cover 720. The post 824 may be heat staked or
otherwise deformed as desired.

[0074]At 1410, the batteries may optionally be inserted in the battery
receiving region 802. The polarity members 910 prevent the negative
terminal of an improperly inserted battery from making electrical contact
with the battery contact 906a.

[0075]At 1412, the bottom cover 720 is attached to the housing body. Note
that the bottom cover 720 may be installed in either of two 180°
opposed positions.

[0076]The lower cover 720 may be removed by depressing the actuating
portions 812a, 812b of the latches 726a, 726b until the engaging portions
814a, 814b disengage from their respective protrusions and moving the
lower cover 720 away from the remainder of the housing. The batteries are
then removed from the battery receiving region through the resultant
opening.

[0077]The above description is considered that of the preferred
embodiments only. Modifications of the invention will occur to those
skilled in the art and to those who make or use the invention. Therefore,
it is understood that the embodiments shown in the drawings and described
above are merely for illustrative purposes and are not intended to limit
the scope of the invention, which is defined by the following claims as
interpreted according to the principles of patent law, including the
Doctrine of Equivalents.